Nasal passages and other portions of the respiratory tract are lined with specialized tissue layers whose integrity and moisture balance provide effective blockade of infectious agents from entering the body. Proper moisturization of the respiratory tract, particularly the nasal passages also increases comfort and reduces risk of epistaxis.
The nasal mucosa is composed of several cell layers and cell types. Mucous cells are present throughout the nasal mucosa and are generally clustered into small glands that secrete a sticky substance called mucus. Mucus is composed of water, shed epithelial (surface) cells, dead leukocytes, mucin, and inorganic salts, among other things, that are all held in suspension.
Mucus functions as a trap for airborne particles (e.g., dust, bacteria, and viruses) that enter the nasal passages. The ciliated columnar epithelia function to remove trapped infectious agents, dust, and other debris trapped in the mucus from the nasal area, thus, protecting the body from developing illnesses. Mucus also lubricates the walls of the nose, sinuses, and throat.
Upper respiratory infections, acute or chronic allergy flare-ups of the nose, and acute or chronic non-allergic rhinosinusitis result in inflammation of the nasal mucosa. This inflammation commonly correlates with the presence of congestion that leads to discomfort and may result from increased blood flow swelling the nasal passages, fluid buildup in the nasal tissues, increased mucus viscosity, and depressed cilia activity. Further irritation may result from additional nasal drying due to subject intervention in attempt to reduce the congestion, the use of some medications, exposure to a low humidity environment, or simple dehydration from failure to consume sufficient fluids.
Thus, there is a need for a composition to increase nasal moisture without exacerbating or reducing cilia activity due to high viscosity to both improve moisturization of the nasal mucosa and reduce congestion.